This invention relates to a well-filler for retaining a tire on a drop-center wheel rim.
A common wheel design of has a rim (known as a drop-center rim) in which there is a comparatively narrow well which effectively reduces the diameter of the wheel all around its circumference. Such a well facilitates the mounting of a pneumatic tire on the wheel. One inextensible bead of a tire is slipped over the lip of a side flange of the rim and into the well and then the diametrically opposite part of that bead of the tire is then able to be passed over the flange and be mounted on the rim. Inflation of the tire forces the beads into their correct position with their feet engaged on slightly conical seats adjacent the flanges.
A major problem with wheels with drop-center rims is that without a device to fill the well there is a danger of the tire detaching itself upon a loss of air pressure, for example after a puncture. One of the beads may slip into the well and the mounting procedure for the tire be effectively reversed. This loss of concentricity involves loss of control, and is dangerous if it happens on a vehicle travelling at high speed.
Band devices for filling wheel wells are known. However, well-fillers of current designs have to be made individually for different types of wheel of different diameter and especially for wells of different effective widths. None of the known well-fillers is adjustable in width. In addition, current designs have to be made in different materials to suit steel and alloy wheels the properties of which vary differently with temperature and load changes.